public static Listener listenOnce(EventTarget src, Union <string, JsArray <string> > type_, Delegate listener, bool opt_capt = false, object opt_handler = null)
{
if (type_.Is <JsArray <string> >())
{
var type = type_.As <JsArray <string> >();
for (var i = 0; i < type.Length; i++)
{
goog.events.listenOnce(src, type[i], listener, opt_capt, opt_handler);
}
return(null);
}
else
{
var type = type_.As <string>();
listener = goog.events.wrapListener(listener);
if (src.isImplementedBy())
{
return(src.listenOnce(type, listener, opt_capt, opt_handler));
}
else
{
//return goog.events.listen_(src, type, listener,
// /* callOnce */ true, opt_capt, opt_handler);
throw new NotImplementedException();
}
}
}
